Answer:
Because the new generation of house buyers have preference toward simplicity during the process of buying new houses.
Step-by-step explanation:
In the past, people who just obtained jobs will try to purchase a less ideal but cheaper houses as their first purchase. Typically this will be beneficial for them because job availability is lower and they're less likely to have to relocate because of new jobs.
The latest generation of house buyers have higher chance to relocate because of new jobs due to the increasing availability.
This is why the demand for single family detached housing developments is increasing. Single family detached housing is typically not for sale, only for rent. The people who live in it doesn't have to pay attention to utilities or fixing their own properties everytime there's something broken. It's much simpler compared to owning your own house. If they renter need to relocate, they can directly do it without having to worry about how to sell the house.